A typical wireless communications system includes a network application server, a plurality of base stations communicatively coupled to the network application server, and a plurality of subscriber units (SUs) that communicate with the network application server by way of the base stations. Generally, when the network application server needs to communicate with the SU, or vice-versa, the SU and the base station currently serving the SU establish a traffic channel through which communications are sent between the network application server and the SU. The process of establishing such a traffic channel, however, is more involved as discussed below.
Generally, an SU will from time-to-time enter into a “dormant mode,” i.e. a low power mode to conserve its internal-battery life. When not in the “dormant mode,” an SU maintains one or more traffic channels with the base station even if the subscriber is not using the device. In the “dormant mode,” however, an SU does not maintain any traffic channels with the base station. Instead, the SU only responds to subscriber initiated actions and periodically monitors the paging channel to determine whether it has been paged.
Typically, when a “dormant” SU needs to communicate with the network application server in response to a subscriber initiated action, the “dormant” SU sends an expedited request packet to the base station currently serving the “dormant” SU. An example of such an expedited request packet is a request to communicate with a target SU. The request packet is expedited because it is transmitted using a common channel since a “dormant” SU does not maintain any traffic channel with the base station. The common channel is a data communication path shared by all SUs currently listening to the base station.
In response to receiving the expedited request packet, the base station attempts to reserve channel resources for a traffic channel to be used by the network application server to communicate with the SU. Additionally, the base station forwards the request packet to the network application server for processing the request.
Once the network application server receives the request packet, it automatically assumes that channel resources for a traffic channel between the base station and the originating SU have been reserved. The network application server then operates as if such channel resources have been reserved, and allows communications to be sent to the base station for transmission to the originating SU by way of the assumed traffic channel.
However, there may be situations when the originator's base station has yet to reserve channel resources for a traffic channel when the network application server receives the request packet. This may be because there are no available traffic channels at such time since they are being used by other subscribers. In such a case, the network application server operates as if such traffic channel has been reserved, and begins allowing communications to be sent to the base station for subsequent transmission to the originating SU. This may lead to a waste of resources since the network application server is performing operations under the assumption that a traffic channel exists, when in fact it does not. And consequently, such operations performed by the network application server may result in the request not being met.